Background/Aims: PreS2-defective hepatitis B virus (HBV) variants may emerge during chronic HBV infection.
These variants carry mutation(s) at the ATG-start-codon and/or in-frame deletion into the preS2 genomic region and
are commonly detected by sequencing analyses. We evaluated the prevalence of these variants in a large series of
chronic HBV infected patients through non-sequencing molecular approaches.
Methods:We examined HBV isolates from 110 HBV carriers: 15 were inactive carriers (IC); 50 had chronic hepatitis
(CH); 25 were cirrhotics; 19 had hepatocellular carcinoma (HCC). The entire preS2 genomic region was amplified by
PCR technique. The amplicons were processed: (A) through electrophoresis on acrylamide gel to reveal deleted
genomes; (B) through electrophoresis on agarose gel after digestion by Nla III enzyme that cuts the wild ATG-startcodon
but not the mutated one.
Results: We detected preS2 variants in 56/110 cases (51%). In particular, we found preS2-defective mutants in 2/15
IC, 25/50 CH, 13/26 cirrhotics, and 16/19 HCC. The presence of these variants was thus significantly associated with
active infection and liver disease (P < 0.002). Moreover, among cases with liver disease preS2-mutants were more
prevalent in HCC patients (P < 0.02).
Conclusions: Our non-sequencing molecular methods are sensitive and specific, and simplify the identification of all
preS2 HBV variant forms. Infection by these variants is significantly associated with active infection and HCC.

Background/Aims: PreS2-defective hepatitis B virus (HBV) variants may emerge during chronic HBV infection.
These variants carry mutation(s) at the ATG-start-codon and/or in-frame deletion into the preS2 genomic region and
are commonly detected by sequencing analyses. We evaluated the prevalence of these variants in a large series of
chronic HBV infected patients through non-sequencing molecular approaches.
Methods:We examined HBV isolates from 110 HBV carriers: 15 were inactive carriers (IC); 50 had chronic hepatitis
(CH); 25 were cirrhotics; 19 had hepatocellular carcinoma (HCC). The entire preS2 genomic region was amplified by
PCR technique. The amplicons were processed: (A) through electrophoresis on acrylamide gel to reveal deleted
genomes; (B) through electrophoresis on agarose gel after digestion by Nla III enzyme that cuts the wild ATG-startcodon
but not the mutated one.
Results: We detected preS2 variants in 56/110 cases (51%). In particular, we found preS2-defective mutants in 2/15
IC, 25/50 CH, 13/26 cirrhotics, and 16/19 HCC. The presence of these variants was thus significantly associated with
active infection and liver disease (P < 0.002). Moreover, among cases with liver disease preS2-mutants were more
prevalent in HCC patients (P < 0.02).
Conclusions: Our non-sequencing molecular methods are sensitive and specific, and simplify the identification of all
preS2 HBV variant forms. Infection by these variants is significantly associated with active infection and HCC.